Planning position

Many installations do not need a full planning application—but never assume

Scottish permitted-development rights can cover one domestic air source heat pump on a home or within its grounds when every limit and condition is met. The address and exact proposed position matter, and your local planning authority remains the right place to confirm a marginal or unusual case.

The “one-metre rule” explained

In Scotland, it is not simply a one-metre distance from the boundary

Current Scottish guidance says a unit attached to the dwelling must not protrude more than one metre from the external surface. It also sets separate conditions for where equipment can sit, its height, the number of units and sound. An old article—or a rule written for another UK nation—can therefore give the wrong answer for a Scottish home.

Attached to the home

The stated one-metre test concerns how far the unit protrudes from the external surface. It is not a universal one-metre boundary rule.

Within the grounds

A freestanding unit must not sit forward of the principal elevation or a side elevation that faces a road, and the resulting structure must not exceed three metres.

One ASHP

The domestic permitted-development class covers one air source heat pump on or within the grounds of the same building. A second unit needs separate planning consideration.

Sound still matters

The proposal must meet the current MCS 020 sound calculation at every relevant assessment position; distance alone does not decide compliance.

Situations that deserve an early planning check

Listed buildings

The domestic permitted-development right does not apply within the grounds of a listed building. Planning and listed-building consent may both need to be considered.

Conservation areas

For equipment on the dwelling, the current permitted-development route restricts the unit to ground-floor level on the rear elevation. Other positions need specific advice.

World Heritage Sites

The domestic permitted-development right does not apply in a World Heritage Site. Ask the planning authority before fixing the design or buying equipment.

Flats and shared property

Planning permission and private rights are separate. A factor, landlord or co-owner may need to agree work on common walls, roofs, gardens or access routes.

How the sound check works

MCS 020 uses the selected unit’s declared sound power, distance, reflections, screening and nearby assessment positions. The current permitted-development method uses a calculated limit of 37.0 dB(A) at every assessment position. Moving the unit or choosing a quieter model can change the result, but any screen must still preserve airflow and maintenance access.

A sound calculation is part of the siting decision; it is not evidence that every unit will be inaudible. FLO can record the proposed position and product data during the survey so planning, neighbour, access and performance questions are considered together.

A sensible pre-installation checklist

  • Confirm whether the building is listed.
  • Check conservation-area or other local designations.
  • Identify boundaries, neighbouring windows and likely outdoor-unit positions.
  • Review the selected unit’s dimensions and sound information.
  • Ask the local planning authority when the position is not clear.
  • Keep the planning conclusion with the project documents.

Planning is only one part of siting

A position can be acceptable in planning terms and still be poor for airflow, service access, pipe length, drainage or appearance. The final location should work technically and practically as well as meeting the relevant rules.

See how airflow, drainage, servicing and appearance affect the outdoor-unit position

Read the extra ownership, access and hot-water questions for flats

Independent sources

Scheme rules and guidance can change. Check these sources before making a financial or planning decision.